Thermoforming Decoration Positioning via Electrostatics

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Solution Overview

Problem

Existing thermoforming processes face challenges in accurately positioning decorations within the thermoforming chamber, leading to potential untimely contact and deformation of the decoration during the thermoforming process, especially when using compatible materials for the container and decoration.

Innovation Solution

The process involves adjusting the decoration's position within the chamber before thermoforming and charging it with static electricity to maintain it against the chamber wall, ensuring precise positioning and avoiding premature contact with the thermoformed container material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the decoration is introduced into the thermoforming chamber before thermoforming, then the decoration can be positioned in the chamber, but the decoration may come into untimely contact with the container material causing deformation

Engineering Contradiction:
Improvedecoration positioning accuracyVSAvoiddecoration deformation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by charging the decoration with static electricity before the thermoforming process begins. This pre-applied electrostatic charge creates an attractive force that holds the decoration against the mold wall in advance, preventing untimely contact with the container material during the stretching phase of thermoforming.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces electrostatic attraction as an intermediary force between the decoration and the mold wall. This electrostatic field acts as a mediator that secures the decoration in position without requiring direct mechanical contact or complex positioning mechanisms, thereby preventing deformation while maintaining simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If static electricity is used to hold the decoration against the chamber wall, then the decoration remains securely positioned, but additional equipment is required

Engineering Contradiction:
Improvedecoration positioning stabilityVSAvoidstatic electricity generation equipment
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by using the decoration's own material properties (its ability to hold an electrostatic charge) to secure itself against the mold wall. The decoration essentially serves its own positioning function through electrostatic attraction, eliminating the need for complex external positioning mechanisms or additional equipment beyond a simple charging device.

Inventive Principle:
Principle #25Self-service

3Strength

If compatible materials are used for the container and decoration, then the decoration sticks to the container after cooling, but the decoration and container material join together prematurely during thermoforming

Engineering Contradiction:
Improvedecoration-to-container adhesionVSAvoiddecoration positioning accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies preliminary anti-action by using electrostatic attraction to counteract the premature adhesive forces between compatible materials during thermoforming. The electrostatic force acts in advance to hold the decoration away from the container material during the critical stretching phase, preventing early contact and deformation, while still allowing the desired adhesion to occur after cooling when the container shrinks.

Inventive Principle:
Principle #9Preliminary anti-action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method ensures the decoration is perfectly positioned and pressed against the chamber wall, preventing untimely contact and deformation, while being cost-effective and simple to implement, as it eliminates the need for complex air suction systems.

Implementation Method 1

charging the decoration with static electricity to maintain the decoration pressed against the wall of the chamber

Methodology Applied
Scientific EffectStatic electricity: Electrostatics

Data Source

PatentEP2429798B1Method and device for thermoforming and decorating containers
Publication Date: 2013.05.01 ERCA SA
  • EP2429798B1 patent drawingFigure 1
  • EP2429798B1 patent drawingFigure 2A~3
  • EP2429798B1 patent drawingFigure 2B

AI summary

The invention relates to a method and to a device for making containers (R) by thermoforming and for applying decorations (32) to said containers. The containers are thermoformed in at least one thermoforming chamber (22) of at least one mold unit (30A, 30B, 30C, 30D) into which a decoration (32) has been inserted. Before thermoforming a container (R), the position of the decoration (32) is adjusted in the chamber (22) and the decoration is charged with static electricity so as to be retained flat against the wall of the chamber containing the same.